By Louise M. Klebanoff, MD
Assistant Professor of Clinical Neurology, Weill Cornell Medical College
Dr. Klebanoff reports no financial relationships relevant to this field of study.
Persistent post-concussion syndrome may last for more than six months, and risk factors include female sex, neck pain, headache, and post-concussive symptoms at two weeks after the injury.
Cnossen MC, van der Naalt J, Spikman JM, et al. Prediction of persistent post-concussion symptoms. J Neurotrauma 2018; Apr 25. doi: 10.1089/neu.2017.5486. [Epub ahead of print].
Mild traumatic brain injury (mTBI), a common condition in the general population, frequently results in persistent post-concussive symptoms (PPCS). Although most patients who develop an acute post-concussive syndrome improve in the days or weeks following the injury, a significant proportion of patients develop persistent cognitive, somatic, and emotional symptoms that can last for six months or longer following the injury. PPCS is associated with reduction in health-related quality of life and with work absenteeism, making it a serious public health concern. Cnossen et al aimed to develop an algorithm to identify patients at risk of developing PPCS based on their initial presenting complaints.
Previous studies aimed at identifying predictors for PPCS have not been validated externally. In addition, these models did not consider the role of acute complaints reported in the ED, such as headache, nausea, vomiting, and neck pain. Using the Dutch multicenter, prospective, observational UPFRONT study, the authors aimed to assess the quality and clinical value of the existing prediction models for six-month PPCS in patients with mTBI and to develop a new model (“The UPFRONT-PPCS model”) based on relevant predictors from existing models and complaints at the ED.
The authors reviewed data from a prospective cohort study conducted in three Level I trauma centers in the Netherlands between 2013 and 2015. They included all patients 16 years of age or older with an admission Glasgow Coma Scale (GCS) score of 13-15, post-traumatic amnesia (PTA), or loss of consciousness (LOC) and who had sufficient comprehension of the Dutch language. They excluded patients with drug or alcohol addiction, homelessness, or dementia. All patients had computed tomography (CT) scanning. The medical records were reviewed for prior TBI, education level, LOC, PTA, and ED complaints of headache, nausea/vomiting, and neck pain. Post-concussive symptoms (PCS) were assessed at two weeks and again at six months using the Head Injury Symptoms Checklist (HISC), a 21-symptom questionnaire. Patients were classified as PCS persisting for two weeks and PPCS persisting for six months if they indicated that at least three of the following symptoms were worse than before the injury: headache, dizziness, fatigue, irritability, difficulties falling asleep or staying asleep, concentration problems, memory difficulties, intolerance of alcohol, or anxiety. Post-traumatic stress symptoms were assessed at two weeks with the Impact of Event Scale.
A total of 1,151 patients were included in the UPFRONT study, of whom 591 (51%) completed the six-month HISC. The included patients had a mean age of 51 years, 41% were female, and 16% had intracranial traumatic abnormalities on their initial head CT. At six months following the injury, 370 patients (63%) reported at least one of eight symptoms and 241 (41%) reported three or more symptoms, fulfilling the criteria for PPCS. The most commonly reported symptoms were fatigue (38%), concentration problems (36%), and memory problems (35%).
Backward selection with all variables resulted in the inclusion of three variables: female sex (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.01-2.18), two weeks PCS (OR, 4.89; 95% CI, 3.19-7.49), and two weeks post-traumatic stress (OR, 2.98; 95% CI, 1.88-4.73). The addition of acute complaints in the ED improved the model, but only neck pain was statistically significantly associated with six-month PPCS (OR 2.58, 95% CI 1.39-4.78). In a univariate analysis, there was a statistically significant association between headache and PPCS.
PCS after two weeks was the strongest predictor in the model. Among the 241 patients with PPCS at six months, 192 (80%) reported three or more symptoms after two weeks and almost all (97%) reported at least one symptom after two weeks. Of the 333 patients reporting three or more symptoms after two weeks, only half (192) still reported three or more symptoms after six months. The authors also found that patients with a GCS score lower than 15, patients admitted to the hospital, patients reporting dizziness, and patients having enhanced scores on the symptoms checklist or the hospital anxiety and depression scale after two weeks had higher odds of developing PPCS in both univariable and multivariable analyses.
COMMENTARY
Mild traumatic brain injury is common in the general population, and persistent post-concussive symptoms cause a significant public health burden. Because of the complexity in developing a predictive model for PPCS, existing models often underestimate the risk of PPCS and have not been validated externally. The authors sought to improve existing models by the adding factors noted at ED presentation. They found that PPCS at two weeks was the strongest predictor. Of the acute symptoms analyzed, neck pain was statistically associated with PPCS; it is thought that concomitant cervical soft tissue injury contributes to PPCS. It may be helpful to be able to predict patients at higher risk for the development of PPCS. Acute interventions, including physical therapy to reduce neck pain, therapy or medications to reduce psychological complaints, and cognitive remediation, could be introduced more readily to those patients at higher risk for the development of PPCS.
